光谱法研究间尼索地平与人血清白蛋白的相互作用

摘要

Objective To study the interactions between m-nisoldipine ( m-Nis ) and human serum albumin ( HSA ). Methods Ultraviolet visible spectroscopy ( UV-vis ) and fluorescence spectroscopy were used to study the spectral behavior of interactions between m-Nis and HSA under different temperature at the physiological pH( 7.4). Results m-Nis did not cause the conformation change of the HAS; The quenching constants at 293K,301K,and 310K were 1. 03 × 105mol/L,1. 25 × 105 mol/L,l. 31 × 105 mol/L, respectively; the number of binding sites ( n ) was nearly 1. The enthalpy change ( △H ) was 3. 695 kj/mol with △G < 0 and △S > 0; The distance between binding site and tryptophan ( r ) = 2. 96nm. Conclusion The mechanism of fluorescence quenching of m-Nis to HSA was neither static nor dynamic fluorescence quenching, but formed 1: 1 complex and resulted fluorescence quenching. The non-radialization energy transfer process occurred betwwen m-Nis and HAS and the action force was hydrophobia interaction.%目的 研究不同温度下间尼索地平(m-nisoldipine,m-Nis)与人血清白蛋白(human serum albumin,HSA)相互作用.方法 采用紫外光谱法和荧光光谱法在模拟人体生理pH=7.4的0.1mol/L磷酸缓冲溶液中研究不同温度下m-Nis与HSA相互作用的光谱行为.结果 m-Nis没有使HSA的构象发生变化.293K、301K和310K时的猝灭常数为分别为1.03×105mol/L,1.25×105mol/L和1.31×105mol/L;结合点数n近似为1,反应的焓变值为3.695kJ/mol,且ΔG<0,ΔS>0;m-Nis在HSA上的结合位置距色氨酸残基的距离(r)=2.96nm.结论 m-Nis对HSA的荧光猝灭作用不是简单的动态猝灭或静态猝灭,而是形成了1∶1的复合物,造成荧光猝灭;m-Nis与HSA之间发生的是非辐射能量转移过程,二者之间的主要作用力是疏水力.